As a follow up, I presented this topic to the CMAG at the October meeting (slides in agenda).
I’ve since built a demonstrator to help illustrate the use case for such a concept map:
UCUMverter - UCUM unit conversion demo.
How it works:
- The Drug selection panel (3) is the only place SNOMED CT is used. You pick an AMT drug concept, and its strength (value and SNOMED CT unit) is read from Ontoserver.
- Every unit field in the app is UCUM coded. The lab and creatinine fields use LOINC codes to choose which UCUM units are offered.
- A draft map converts the drug’s SNOMED CT unit to UCUM. This is the only SNOMED CT to UCUM step.
- All unit conversion after that is done in UCUM, using the official NLM lhncbc/ucum-lhc library.
This is the complete (informal) map the demonstrator uses:
{
"_comment": "DRAFT 1:1 map from SNOMED CT-AU unit concepts (as used in AMT strength properties) to UCUM codes.",
"map": {
"258684004": { "display": "mg", "ucum": "mg" },
"258682000": { "display": "g", "ucum": "g" },
"258685003": { "display": "microgram", "ucum": "ug" },
"258773002": { "display": "mL", "ucum": "mL" },
"258770004": { "display": "L", "ucum": "L" },
"258774008": { "display": "microlitre", "ucum": "uL" },
"258718000": { "display": "mmol", "ucum": "mmol" },
"258719008": { "display": "micromol", "ucum": "umol" },
"258798001": { "display": "mg/mL", "ucum": "mg/mL" },
"258796002": { "display": "mg/L", "ucum": "mg/L" },
"258797006": { "display": "mg/dL", "ucum": "mg/dL" },
"258801007": { "display": "microgram/mL", "ucum": "ug/mL" },
"258799009": { "display": "microgram/L", "ucum": "ug/L" },
"258806002": { "display": "nanogram/mL", "ucum": "ng/mL" },
"258802000": { "display": "microgram/g", "ucum": "ug/g" },
"258803005": { "display": "microgram/kg", "ucum": "ug/kg" },
"258997004": { "display": "international unit", "ucum": "[iU]" },
"732935002": { "display": "each", "ucum": "{each}" }
}
}